In the field of this invention it is known that for optimum transfer of energy, from devices such as power amplifiers, the output impedance of the power amplifier should match the input impedance of circuitry driven by the power amplifier. In practice, the output impedance of a power amplifier such as an integrated circuit (IC) power amplifier (PA) is typically matched by use of an electrical/electronic network including components such as inductors and capacitors mounted externally to the IC and connected to the IC by wires. Wire-bonding is typically used to connect the wires. Capacitors may be metal-oxide-semiconductor capacitors (MOSCAPs) or Surface Mounted Device (SMD) capacitors. Inductors are generally made with transmission lines, such as microstrip or coplanar lines, shunted to ground at a precise position by the abovementioned capacitors.
However, this approach has the disadvantage(s) that the SMD capacitors have, for cost purpose, a poor quality factor which results in losses and a non-negligable series parasitic inductance that narrows the bandwidth, as well as a large tolerance which degrades the PA RF performance deviation over a number of performance parameters. In addition, such SMD capacitors, as they are automatically picked and placed, have minimum spacing specifications in order to fit the assembling machine constraints, thus contributing to increase the overall Power Amplifier application size.
A need therefore exists for impedance matching wherein the abovementioned disadvantage(s) may be alleviated.